Low-temperature dyeing process for acrylic fibers

ABSTRACT

A low temperature dyeing procedure for acrylic fibers is disclosed which makes use of a dyebath comprising dyestuff, chlorinated hydrocarbon, nonionic surfactant, and water.

United States Patent [191 Abeta Nov. 13, 1973 [54] LOW-TEMPERATURE DYEING PROCESS 3,632,302 1/1972 12111561161 8/177 AB 3,617,211 11/1971 Dawson 8/173 FOR ACRYLIC FIBERS [75] Inventor: Sadaharu Abeta, Toyonaka, Japan [73] Assignee: American Cyanamid Company,

Stamford, Conn.

' [22] Filed: Dec. 17, 1971 [21] App]. No.: 209,457

[52] U.S. Cl 8/174, 8/177 AB [51] Int. Cl D06p 3/76 [58] Field of Search 8/177 AB, 174, 173

[5 6] References Cited UNITED STATES PATENTS 2,828,180 3/l958 Sertorio 8/62 Primary Examiner-Leon D. Rosdol Assistd'nt Examiner-T. J. Herbert, Jr. Attorney-William J. Van Loo [57] ABSTRACT A low temperature dyeing procedure for acrylic fibers is disclosed which makes use of a dyebath comprising dyestuff, chlorinated hydrocarbon, nonionic surfactant, and water.

10 Claims, No Drawings LOW-TEMPERATURE DYEING PROCESS FOR ACRYLIC FIBERS This invention relates to a low temperature dyeing procedure for acrylic fibers. More particularly, this invention relates to a process for dyeing acrylic fibers wherein by use of dyebath medium comprising chlorinated hydrocarbon, non-ionic surfactant, and water low temperature dyeing is achieved with basic dyes.

When acrylic fibers are dyed at a high temperature for a long period of time, the properties of the fibers are greatly degraded and therefore, for preventing the occurrence of such degradation, various low-temperature dyeing processes have been proposed. However, conventional processes proposed for such purpose are conducted using carriers such as cresol, phenol, etc., which use results in swelling and injuring the fibers although the fibers may be dyed at a low temperature.

In accordance with the present invention, there is provided a process for dyeing acrylic fibers with basic dyes using as the dyebath medium one comprising a chlorinated hydrocarbon of low boiling point, water, and a nonionic surface active agent. Use of the medium described overcomes the difficulties of the conventional processes.

Water and nonionic surfactant dissolve the basic dyestuff and emulsify the highly concentrated aqueous dye solution in the chlorinated hydrocarbon.

Previously dyebaths were prepared by dissolving a basic dyestuff in an organic solvent such as dimethyl formamide, formamide, or 2-pyrrolidone and adding such solution to a chlorinated hydrocarbon. However, use of such dyebath required a high temperature and the dyed products obtained therewith were inferior in lightfastness compared to dyed products obtained by conventional procedures.

A preferred nonionic surface active agent used in the process of the present invention is a compound having a chain of at least three glycol ether units and there are no particular limitations with respect to hydrophobic groups.

According to the present invention, by dyeing acrylic fibers, particularly acrylic fibers modified to contain basic dye sites, at temperatures below 90C. for 30-60 minutes, dyed products having the same tinctorial strength and fastness as those dyed at 100C. by conventional procedures are obtained. The fibers obtained have a good appearance, i.e., no injury thereto is suffered in the dyeing process, and the dyeing is greatly improved in light fastness compared to the former processes.

Useful chlorinated hydrocarbons include trichloroethylene, l,l,l-trichloroethane, and perchloroethylene. The boiling point of the chlorinated hydrocarbon should be below about 125C.

In preparing the dyebath in accordance with the present invention, the amount of dyestuff employed is that amount which produces the desired color shade in action products of nonyl phenol and ethylene oxide in proportions sufficient to produce ethylene glycol ether chains of at least three ether units, preferably 15 to 20 ether units. Other reaction products may be obtained using octyl phenol and ethylene or propylene oxides. The amount of surfactant employed should be sufficient to produce a water-in-oil emulsion. Use of from about 0.1 to 5 percent surfactant is generally useful, the percentage being by weight, based on the weight of water.

The amount of chlorinated hydrocarbon employed will generally consist of percent or more of the dyebath composition by weight thereof.

Acrylic fibers useful in the dyeing process are those based on acrylonitrile homopolymers or copolymers or mixtures thereof. The copolymers generally contain at least 70 percent acrylonitrile, preferably at least percent acrylonitrile, by weight, based on the total weight of the polymer, and the balance of one or more monomers copolymerizable therewith. Particularly useful polymers are those containing basic dye sites, as are well known and obtained by employing as a comonomer one containing acid groups or by carrying out the polymerization in the presence of a redox catalyst system which provides acid groups as terminal groups on the polymer chains, such as sodium chloratezsodium bisulfite redox system.

In carrying out the dyeing process, the ratio of dyebath to fiber may vary widely, generally from about 2:1 to 20:1 or more respectively. The fibers are entered into the dyebath and dyeing is carried out at a temperature below C. for a time sufficient to effect the level of dyeing desired, generally from about 30 minutes to about 60 minutes. Preferably, dyeing is carried out at a temperature in the range of 75C. to 87C. for about 30 minutes. In such embodiment, the fiber is generally entered into the dyebath at a lower temperature and then heating to the desired temperature is effected.

The dyestuffs useful in the process of the present invention are basic dyestuffs and include the various members of this conventional dyestuff classification.

The invention is illustrated by the examples which follow wherein all parts are by weight.

EXAMPLE 1 To this solution were added 10 parts of-the reaction product of 1 mole of nonyl phenol and 20 moles of ethylene oxide. The resulting solution was then added to 2,500 parts of perchloroethylene with stirring to provide the dyebath. To the dyebath were added 1,000 parts of an acrylic fiber obtained by wet-spinning an acrylonitrile copolymer consisting of 91 percent acrylonitrile, 8.73 percent methyl acrylate, and 0.27 percent sodium methallylsulfonate, the percentages being by weight, based on the total weight of copolymer. The fiber was entered into the dyebath at 25C. and the dyebath was then heated to 87C. and held at this temperature for 30 minutes to effect dyeing. There was obtained a deep pink dyeing having excellent fastness properties. Lightfastness of the dyeing was 5-6. By way of comparison, when dimethyl formamide was substituted for the water and nonionic surfactant used in this example, the resulting dyed fiber exhibited lightfastness of 2. Thus, the surprising increase in lightfastness achieved by the process of the present invention is readily apparent.

EXAMPLE 2 In 400 parts of water were dissolved 2 parts of the basic dye having the following structural formula To this solution were added parts of the reaction product of 1 mole of nonyl phenol and moles of ethylene oxide. The resulting solution was then added to 20,000 parts of perchloroethylene with stirring to provide the dyebath. To the dyebath were added 1,000 parts of an acrylic fiber sold under the trade-name Vonnel 17 (registered trademark) by Mitsubishi Vonnel Co., Japan. The fiber was entered into the bath at 25C. and the bath was heated to 85C. where it was maintained for 30 minutes to effect dyeing. The dyeing was of clear turquoise color and exhibited excellent fastness to light.

EXAMPLE 3 In 400 parts of water were dissolved 2 parts of the basic dye of Example 2. To this solution were added 10 parts of the reaction product of 1 mole of nonyl phenol and 15 moles of ethylene oxide. The resulting solution was then added to 20,000 parts of trichloroethylene with stirring to provide the dyebath. To the dyebath at 35C. were added 1,000 parts of the acrylic fiber of Example l. The dyebath was then heated to 75C. and maintained at this temperature for 30 minutes to effect dyeing. The dyeing was of clear turquoise color and exhibited excellent light fastness.

I claim:

1. A process for dyeing acrylic fibers based on acrylonitrile polymers containing at least 70 weight percent acrylonitrile and the balance of one or more monomers copolymerizable therewith which comprises the steps of (a) preparing a dyebath comprising a basic dyestuff,

sufficient water to dissolve said dyestuff, a nonionic surfactant, and a chlorinated hydrocarbon, the amount of surfactant being sufficient to emulsify said dye solution in said chlorinated hydrocarbon as a water-in-oil emulsion, the amount of water being from about I to about 20 percent, the amount of chlorinated hydrocarbon being about 80 percent or more, said percentages being by weight based on the total weight of dyebath, and the amount of surfactant being from about 0.1 to 5 percent, based on the weight of water, (b) entering an acrylic fiber into said dyebath, and (c) carrying out dyeing at a temperature in the range of about 75C. to below about 90C. for a time of about 30-60 minutes to effect coloration of said fiber.

2. The process of claim 1 wherein said chlorinated hydrocarbon is perchloroethylene.

3. The process of claim 1 wherein said chlorinated hydrocarbon is trichloroethylene.

4. The process of claim 1 wherein said nonionic surfactant is the reaction product of 1 mole of nonyl phenol and 20 moles of ethylene oxide.

5. The process of claim 1 wherein said nonionic surfactant is the reaction product of 1 mole of nonyl phenol and 15 moles of ethylene oxide.

6. The process of claim 1 wherein the temperature of dyeing is in the range of 7587C.

7. The process of claim 1 wherein the temperature of dyeing is 75C.

8. The process of claim 1 wherein the temperature of dyeing is 85C.

9. The process of claim 1 wherein the temperature of dyeing is 87C.

10. In the process of dyeing acrylic fibers based on acrylonitrile. polymers containing at least weight percent acrylonitrile and the balance of one or more monomers copolymerizable therewith with basic dyestuffs at a temperature in the range of about C. to below 90C., the improvement which consists of employing as the dyeing medium one comprising water, nonionic surfactant and chlorinated hydrocarbon, the water being present in sufficient quantity to dissolve the basic dyestuff and the nonionic surfactant being present in sufficient quantity to emulsify the dye solution in said chlorinated hydrocarbon as a water-in-oil emulsion, the amount of water being from about 1 to about 20 percent, the amount of chlorinated hydrocarbon being about percent or more, said percentages being by weight based on the total weight of dyebath, the amount of surfactant being from about 0.1 to 5 percent based on the weight of water, and the dyeing time being from about 30 to 60minutes.

* w: n: s 

2. The process of claim 1 wherein said chlorinated hydrocarbon is perchloroethylene.
 3. The process of claim 1 wherein said chlorinated hydrocarbon is trichloroethylene.
 4. The process of claim 1 wherein said nonionic surfactant is the reaction product of 1 mole of nonyl phenol and 20 moles of ethylene oxide.
 5. The process of claim 1 wherein said nonionic surfactant is the reaction product of 1 mole of nonyl phenol and 15 moles of ethylene oxide.
 6. The process of claim 1 wherein the temperature of dyeing is in the range of 75*-87*C.
 7. The process of claim 1 wherein the temperature of dyeing is 75*C.
 8. The process of claim 1 wherein the temperature of dyeing is 85*C.
 9. The process of claim 1 wherein the temperature of dyeing is 87*C.
 10. In the process of dyeing acrylic fibers based on acrylonitrile polymers containing at least 70 weight percent acrylonitrile and the balance of one or more monomers copolymerizable therewith with basic dyestuffs at a temperature in the range of about 75*C. to below 90*C., the improvement which consists of employing as the dyeing medium one comprising water, nonionic surfactant and chlorinated hydrocarbon, the water being present in sufficient quantity to dissolve the basic dyestuff and the nonionic surfactant being present in sufficient quantity to emulsify the dye solution in said chlorinated hydrocarbon as a water-in-oil emulsion, the amount of water being from about 1 to about 20 percent, the amount of chlorinated hydrocarbon being about 80 percent or more, said percentages being by weight based on the total weight of dyebath, the amount of surfactant being from about 0.1 to 5 percent based on the weight of water, and the dyeing time being from about 30 to 60 minutes. 